Work

Microbial Responses to the Physicochemical Properties and Reactor’s Operational Parameters in Vinasse Digestion in a Pilot-Scale Hybrid Anaerobic Reactor

Year: 2026

Type: article

Abstract: Physicochemical and operational parameters affect microbial communities, impacting anaerobic digestion (AD) systems. Microbial dynamics in response to these parameters were temporally investigated by DNA and cDNA of the 16 S rrna gene in a pilot-scale hybrid anaerobic reactor (HAnR) fed with sugarcane vinasse. Key microbes for biogas production, including Bacteroidetes -vadinHA17, Paludibacteraceae -H1, Prolixibacteraceae , Desulfovibrio , Syntrophobacter and Methanospirillum , were favored by the maintenance of volatile fatty acids (VFA) < 3700 mg.L − 1 , pH ≥ 5.6, temperature ≥ 29.8 °C, chemical oxygen demand (COD) < 31.4 g.L − 1 and organic loading rate (OLR) < 9.7 kg.COD.m − 3 .d − 1 . Temperature and pH also favored the redundancy of fermentation and H 2 -mediated methanogenesis and the evenness and diversity indexes, all related to biogas quality. Concentrations up to 2,050 mg.SO 4 2− .L − 1 , 3,270 mg.K.L − 1 , 367 mg.Mg.L − 1 , 0.4 mg.Cu.L − 1 and 1.1 mg.Zn.L − 1 led to adverse effects over microbial abundance, functional redundancy and ecology, but tolerant microorganisms, like Paludibacteraceae , Anaerolineaceae and Methanosaeta , kept fermentation and methanogenesis ongoing, although less efficiently. Microbial interactions were also affected by evaluated parameters beyond metabolic dependence. This study highlights the importance of parameter monitoring in scaled-up AD reactors to promote the adequate establishment of microbial communities and therefore contribute to system stability.

Source: BioEnergy Research

DOI: 10.1007/s12155-025-10950-9